1. Field of the Invention
The present invention relates to a Tee nut, and more particularly, it relates to a Tee nut which is provided with a portion to be caulked on its shaft portion.
2. Description of the Background Art
For example, U.S. Pat. No. 5,238,344 describes a conventional Tee nut, which is of interest to the present invention. This Tee nut comprises a shaft portion and a flange portion outwardly extending from a first end of this shaft portion, which are prepared from an integral metal material. The shaft portion is in the form of a hollow cylinder and provided with a portion to be caulked on a second end which is opposite to the first end, while a female threading is formed on its inner peripheral surface excluding the portion to be caulked. Further, a plurality of pawls are provided on the outer peripheral edge of the flange portion, to project toward the second end of the shaft portion. In the shaft portion, the portion to be caulked is reduced in thickness as compared with that provided with the female threading, to facilitate caulking.
The shaft portion is inserted in a hole which is provided in an work piece such as a wood member, for example, and the pawls are driven into the work piece while the portion to be caulked is caulked to be spread on the side of a surface of the object which is opposite to that receiving the flange portion, so that the Tee nut is fixed to the work piece.
The hole provided in the aforementioned work piece is generally formed with a drill, or by punching.
In order to fix the Tee nut to a work piece, a hole for receiving the shaft portion of the Tee nut is generally previously provided in the work piece. When the Tee nut is to be fixed to the work piece by an automatic machine, however, it is necessary to properly align the Tee nut with the hole which is previously provided in the work piece, and relatively high accuracy is required for such alignment. While a relatively large hole may be provided in the work piece to enable rough alignment with the Tee nut, the as-fixed Tee nut is problematically rattled in this case with respect to the work piece.
In order to fix the Tee nut to the work piece, further, a step of providing a hole in the object is required in advance, and hence the number of steps is increased.